Evolved Node Bs (eNBs) in the Long Term Evolution (LTE)/Long Term Evolution-Advanced (LTE-A) system are distributed eNB devices, each of which is composed of a Base Band Unit (BBU) and a Radio frequency Remote Unit (RRU) as a combined eNB that can be deployed in a flexibly distributed manner, as illustrated in FIG. 1, in which the RRU is connected with the BBU via an Ir interface.
The transmission medium in the existing Ir interface is an optical fiber or another transmission medium, and if data over the Ir interface is compressed technically in effect, then a demand for the transmission medium can be greatly alleviated to thereby lower the cost of the device and improve the competitiveness of the product in the market.
In the LTE system, there is such an existing solution to compression of data over the Ir interface that an automatic gain adjustment is performed on the input signal to thereby control a dynamic range of the signal and to lower the quantified bit width of the signal in a uniform quantification algorithm. This solution can compress data with a 16-bit bit width into 12 bits, which means a compression ratio of 4:3 representing the ratio of the size of the compressed data to the size of the uncompressed data, while ensuring the reliability of the signal.
As can be apparent, there is low compression ratio in the prior art, and the algorithm may not be widely applicable, due to the fact that the uniform quantification is an optimum quantifier for a uniformly distributed input signal, whereas the simple uniform quantification may not be reasonable to allocation of quantification levels for a non-uniformly distributed input signal because redundant components in the signal may not be removed sufficiently.